Method of and apparatus for bias laying

ABSTRACT

A multi-ply bias laid ribbon is formed by an apparatus and a method in which at least one web is spirally wound onto a flat, vertically disposed mandrel as the web discharges at a helix angle from a web guiding and folding bar means. The latter is carried in a circular path about the mandrel and shifted vertically at substantially the speed of travel of web receiving mandrel belts during application of the web onto the mandrel belts.

Lee et a1. Dec. 9, 1975 [5 METHOD OF AND APPARATUS FOR BIAS 3.263.512 8/1966 Handley 74/54 LAYlNG 3,510,382 5/1970 Wideman et a] 156/425 [75] Inventors: Charles A. Lee; Warren R. Furbeck, FOREIGN PATENTS OR APPLICATIONS both of Knoxville, Tenn.

283,046 1/1928 United Kingdom .1 156/422 X [73] Assignee: International Paper Company, New

York, NY. Primary ExaminerCharles E. Van Horn [22] Flled' Dec. 1972 Assistant ExaminerDavid A. Simmons [21] Appl. No: 311,313 Attorney, Agent, or FirmFitch, Even, Tabin & [44] Published under the Trial Voluntary Protest Luedeka Program on January 28, 1975 as document no.

Related US. Application Data [63] g gz gg g x g A multi-ply bias laid ribbon is formed by an apparatus and a method in which at least one web is spirally [52] Us. CL H 156/425; 74/27. 156/429. wound onto a flat, vertically disposed mandrel as the 156/194 web discharges at a helix angle from a web guiding [51] Int. cu B6511 81/00 and fading bar The is Carried in 3 58 Field of Search 156/425- 432 Path about mandrel and Shifted vertically 156/189, 194, 193, 195, 494, 422 93/80: substantially the speed of travel of web receiving man- 226/I97, 19 242 4707. 74 27 5 Cll'el bCltS during application Of the web OlltO the man- 1 drel belts.

[56] References Cited UNlTED STATES PATENTS Dmwmg Figures 2,880,781 4/1959 Carlson 156/494 X 192 i e QIQU [9595a G /a7 35 4 4 7 I 2 g 47 z ggq a 15 I 4 m f 13 N /4/ US. Patent Dec. 9, 1975 Sheet 2 of8 3,925,142

U.S. Patent Dec. 9, 1975 Sheet 3 of8 3,925,142

U.S. Patent Dec. 9, 1975 Sheet 4 of8 3,925,142

US. Patent Dec. 9, 1975 Sheet 5 of8 3,925,142

RQ m a m$ RS 0% 5 A Q T m5 W 6 Aw U.S. Patent Dec. 9, 1975 Sheet 6 of8 3,925,142

mirl pf U.S. Patent Dec. 9, 1975 Sheet 7 of8 3,925,142

US. Patent Dec. 9, 1975 Sheet 8 of8 3,925,142

METHOD OF AND APPARATUS FOR BIAS LAYING This application is a continuation-in-part application of our earlier application Ser. No. 96,756 filed Dec. 7, 1970, now US. Pat. No. 3,7l5,255 which is entitled Method of and Apparatus for Bias Laying with a Flat Mandrel" and which is assigned to the assignee of this invention.

This invention relates to a method of and an apparatus for producing a continuous flat multi-ply product by spirally winding at least one web of material into a hollow tube and then flattening the tube to form a ribbonlike product having superimposed bias laid plies.

The apparatus disclosed in this above-identified copending application comprises an overhead carrier carrying parent rolls of web material in a circular path about a central vertical axis extending through a vertically extending flat mandrel beneath the carrier. The flat mandrel is formed with two vertically travelling belts spaced horizontally from each other and centered about the carriers axis of rotation. The web is applied in a spiral manner to the flat belt mendrel and at a lead or helix angle to the vertical with the mandrel belts continuously moving the helically formed tube thereon in a downward direction. The webs discharge from parent rolls on the carrier in a flat horizontal plane and travel across a folding bar means which reorients the web into a vertical on-edge plane and discharges the same at the predetermined helix angle to the mandrel. The web is applied to each of the pair of mandrel belts at about 180 intervals.

Despite attempts to control and maintain the web tension and its travel speed across the folding bar means and onto and along the mandrel, these relatively large width webbs, for example 84 to 102 inches in width, may become wrinkled, twisted or uneven in some areas thereby adversely affecting the appearance of the final product. From a commercial standpoint, the bias laid product should be free of wrinkles or other distortions which mar the aesthetics thereof. Better control of the webs is also needed when increasing the speed of operation of these machines to that desirable for paper converting or the like operations.

It has been observed that with the above-described apparatus, the angle defined by the web between the discharge folding bar and a mandrel belt is continually changing in both the horizontal and vertical directions. The angle in the horizontal plane is continually changing as the discharging folding bar swings from a position close to the mandrel bar and then outwardly in a semi-circular path toward the other mandrel belt. In the vertical direction, the mandrel belt having the web thereon is moving downwardly while the discharging folding bar remains at a fixed vertical height. Also, it has been observed that when the discharging folding bar is most closely adjacent a mandrel belt and is applying the web thereto, the web appears to be almost stationary and to actually twist slightly on the vertically moving mandrel belt at the time of application.

In accordance with the present invention, the web or webs are discharging from a folding bar means and are traveling to the mandrel at a substantially constant angle in the vertical plane while traveling at a substantially constant velocity to the mandrel belts irrespective of the position of the carrier in its circular path of travel. Thus, the web may be applied more evenly and uniformly to the mandrel belts to alleviate wrinkling 2 and twisting of the web on the mandrel thereby providing a more smooth and uniform bias laid ribbon product.

Accordingly, a general object of the invention is to provide an improved method of and apparatus for bias laying webs on a flat mandrel from a carrier traveling in a circular path about the mandrel.

Other objects and advantages of the invention will become apparent from the following detailed description taken in connection with the drawings in which;

FIG. 1 is a fragmentary perspective view of a bias laying apparatus embodying the novel features of the invention;

FIG. 2 is a diagrammatic perspective view of a cam and cam follower means;

FIG. 3 is an elevational view of a folding bar assemy;

FIG. 4 is a side view of FIG. 3;

FIG. 5 is a fragmentary, plan view of a cam and cam follower means;

FIG. 6 is an elevational view of a supporting frame for the cam follower means;

FIG. 7 is a side view of FIG. 6;

FIG. 8 is a diagrammatic view in elevation of the apparatus of FIG. 1;

FIG. 9 is a plan view of the cam ring; and

FIG. 10 is a diagrammatic graph of the movement of the folding bar assemblies during a rotation of the carrier.

As shown in the drawings for purposes of illustration, the invention is, as best seen in FIGS. I and 8, embodied in an apparatus 11 for forming a bias laid product by rotating a carrier 12 having one or more parent supply rolls 14 from which continuous webs 15 are stripped for traveling across a web guide means and folding bar means 17 to discharge at bars 18 for spanning gaps to a vertically disposed flat mandrel 19. The mandrel 19 comprises generally a pair of vertically disposed mandrel belts 21 and 23 to which each web is applied during a revolution of the carrier 12. The web is generally spirally wound about the mandrel to form a tube 24 with edges of the webs abutted or overlapped. The tube discharges from the lower end of the mandrel 19 into the nip of a pair of rolls 25 which flatten the tube and form a multi-ply bias laid, endless, ribbon-like product 26.

As disclosed in the above-mentioned application and in US. Pat. No. 3,580,784, the carrier 12 is suspended in a box-like frame 27 and journaled for rotation about a vertically extending stationary post 29 which is at tached at its upper end to the frame 27. The carrier 12 rotates about a vertical axis 28 through the post 29 and the axis 28 extends vertically downward through the mandrel 19 at a central location between the mandrel belts 21 and 23. The mandrel 19 is fixedly secured at its upper end to the lower end of the post 29 which extends downwardly through a central opening in the bottom of the carrier. In the aforementioned co-pending application, the mandrel was suspended from the carrier and was rotated in a reverse direction and at a speed equal to carrier speed to maintain in the mandrel l9 stationary relative to the nip rolls 25 into which the web tube is discharged. As will be explained in greater detail hereinafter, the mandrel belts 21 and 23 are driven at speeds correlated with the carriers rotational velocity and the unwind speed of the webs 15 from the parent rolls 14. Rather than fixing the mandrel 19 directly to the post 29, it may be suspended from and driven in a reverse direction by an orbital drive means as disclosed in the aforementioned application and US Pat. No. 3,580,784.

The carrier 12 carries the web discharging bars 18 in circular paths and at fixed radial locations from the vertical axis 28 through the mandrel 19. Herein, the web 15 extends from the discharging bars 18 to the mandrel belts 21 and 23 at identical angles, e.g., 42 to the hori zontal, as seen in FIG. 8, to wrap the helically wound tube 24 on the mandrel 19. The web 15 may be laid at other angles than 42 to the horizontal and still fall within the purview of the invention. As best seen in FIG. 9, the web discharge bars 18 travel in a closed circular path 31 and are close to the mandrel belts at points A and then for 180 travel about a circular path 31 away from the mandrel beltsv In the apparatus disclosed in the aforementioned copending patent application, the mandrel belts disclosed therein continually carry downwardly the webs applied thereto at the points while the webs on the web discharge bars remained at a fixed vertical height and, as a result, the angle of the webs between the discharge bars and mandrel belts was changing, particularly as the webs were brought against and then wrapped slightly around the mandrel belts. The initial portion of the webs engaging the mandrel belt was immediately carried downwardly by the belt while the adjacent portions of the webs moving across the folding bars were not moving downwardly. Thus, the webs tended to twist when being applied to the mandrel belts. Also in the horizontal direction. the angles of the webs, shown here as B in FIG. 8, continually changing as the web discharge bars travel at a fixed radial location about the axis through the mandrel. It was observed with the apparatus disclosed in the aforementioned application that when the discharge bars were adjacent to the mandrel belts, the webs discharged quite slowly across the bars in contrast to the web travel across the bars at 30 later. While dancer rolls (such as dancer rolls 34 shown in FIGS. 1 and 8) were used to take up and pay out the webs to provide a substantially constant tension for the webs. they do not assure a uniform web travel velocity irrespective of the position of the discharging bars relative to the mandrel belts. While the apparatus disclosed in the aforementioned application was generally satisfactory, the changing angles and speed sometimes resulted in wrinkles or other distortions in the bias laid product.

In accordance with the present invention, the web guide and folding bar means 17 is shifted vertically as it revolves about the mandrel to provide a relatively constant angle for the web 15 extending between the folding bars 18 and the mandrel belts 21 and 23, particu larly at points A of application of the webs to the mandrel belts; and this also provides a more uniform discharge velocity for the webs across the bars 18. This vertical shifting is achieved by a cam means 32 and a cam follower means 33 operably connected to the web guide and folding bar means 17 to shift them vertically in a controlled manner during their travel in a closed circular path about the mandrel 19. As will be explained in greater detail, the web discharging bars 18 are displaced vertically so that the resultant sum of the radial and vertical vectors of web travel remains at a substantially constant value throughout each segment of the carriers revolution. Also, as will be seen hereinafter. at the point of application of the webs to mandrel elts, the bars 18 are traveling downwardly with the 4 belts 21 and 23 at substantially the belt travel speed. The longitudinally extending edges of each of the webs spanning the gaps from the bars 18 to the mandrel belts are kept taut so that one edge does not become loose and the other edge tight when applied to the mandrel 19.

While the cam means 32 could be vertically disposed, the illustrated cam means 32 is located in a horizontal plane and the cam follower means 33 converts horizontal displacements thereof by this cam means into a vertical displacement of the web discharging bars 18. As both the movable web guide and folding bar means 17 and their web discharging bars 18 are identical as both the cam follower means 33 are identical for operating each of them, a description of a single one of the cam follower means 33 and the web guide and folding bar means 17 will suffice for an understanding of the other.

Referring now in greater detail to the individual elements of the invention, the movable web guide and folding bar means 17 receives the web 15 from a web tensioning dancer roller 34 with the web undergoing a change in direction from a generally horizontal to a generally vertical disposition as the web travels across to the web guide and folding bar means 17 and turns downwardly thereon. As best seen in FIGS. 1, 3 and 8, the web is turned on edge on the folding bar means 17 and extends at a helix angle to spirally wrap on the mandrel 19. As best seen in FIGS. 1 and 8, the web 15 discharges from its parent roll 14 which is supported on a spindle 35 supported by cross arms 36 of a carrier frame 37 which includes an upstanding stand 38 and a supporting beams 39 beneath floor plates 40 supported by the beams. The carrier floor plates 40 have arcuate edges 41 which define a cricular opening in a stationary floor 42 carried by the outer box frame 27. The floor plates 40 in the carrier 12 are spaced at the center thereof to allow the main supporting shaft 29 to extend to the bearing 30 which is also carried by the carrier frame 37. Slots 43 are also formed in the carrier floor plates 40 to allow the web 15 to travel downwardly beneath the floor level and to allow a folding bar 46 of the upper portion of the web guide and folding bar means 17 to extend upwardly of the floor level.

The folding bar 46 extends horizontally and the web 15 travels thereacross and turns from a horizontal disposition to a vertical disposition for traveling downwardly through the slot 43 and to an inclined folding bar 47 of a folding bar assembly 48 which is shown in detail in FIGS. 3 and 4. As best seen in FIGS. 1, 3 and 8, the web 15 travels downwardly from the horizontal folding bar 46 to the inclined folding bar 47 about which it turns inwardly toward the axis 28 and then diagonally across to the outer side of the folding bar 18 to extend at the helix angle to the mandrel 19.

The folding bar assembly 48 comprises, as best seen in FIGS. 1 and 3, a pair of upper vertically extending parallel slide rods 49 and 51 joined in a generally rectangular frame by the upper folding bar 46 and a lower cross brace 53. At their upper ends, the slide rods 49 and 51 are fastened to the folding bar 46 by brackets 55 and are fastened at their lower ends to the cross brace 53 by the tie bar blocks 57. The inclined folding bar 47 is pivotally mounted at its lower end on a slide or tie base 59 carrying a bracket 61 having a pivot pin 63 inserted through an aperture in the inclined folding bar 47. The latter elxtends upwardly at an angle to its upper end which is connected by means of a pin 64 to the bracket 55. An inclined brace bar 65 is rigidly fastened at its lower end by a bracket 69 to the slide base 59 and is rigidly fastened at its upper end by a bracket 70 fixed to the tie bar block 57 on the slide bar 49. An oppositely inclined brace bar 67 is rigidly fastened at its lower end by a bracket 68 to the tie base 59 and is rigidly fastened to the tie bar block 57 by a bracket 71. Preferably, the folding bars 46 and 47 as well as the brace bars 65 and 67 are hollow aluminum tubes to provide strength and rigidity for a lightweight folding bar assembly 48.

The folding bar assembly 48 is guided for rectilinear movement relative to the carrier 12 by slide means in the form of ball bushings 73, 74 and 75. In this instance, a pair of ball bushings 73 shown in FIG. 3 are carried on the upper ends of vertical posts 76 (FIG. 1) of the carrier frame 37, the upper ends of the posts 76 carrying the bushings, having been broken away in FIG. 1 for the purpose of clarity. The slide rods 49 and 51 are preferably precision steel rods which are disposed vertically and slide within the ball bushings 73 and guide the upper end of the folding bar assembly 48 for rectilinear vertical movement. At the lower end of the folding bar assembly 48, adjacent the folding bar 18, the lower ball bushing 75 is fixed to the tie base 59; and the ball bushing 75 slides along a vertically extending precision shaft 77 which in turn is fixed to the carrier 12 by means including brackets 78. As best seen in FIGS. 3, 5 and 7, the ball bushing 74 is affixed to the tie base 59 adjacent the lower end of the inclined brace 65 to slide along a stationary vertically extending rod 79 supported on the carrier 12 by means including brackets 80. Thus, it will be seen that the ball bushing 73, 74, 75, and the rods 49, 51, 77 and 79 guide the folding bar assembly 48 for vertical rectilinear movement relative to the carrier 12 when actuated by the cam follower means 33 which is connected to the base 59 of the folding bar assembly 48 as will now be described.

As best seen in FIGS. 2 and 5, the folding bar assembly 48 is displaced vertically in accordance with movement of a cam follower means 33 which comprises a bell crank means 81 which converts its horizontal displacement into a vertical displacement of the assembly 48. More specifically, the bell crank means 81 includes a bell crank 83 which is pivotally mounted on a pivot shaft 84 fastened to a pair of upstanding columns 85 as best seen in FIGS. 6 and 7. The upper end of the bell crank 83 is provided with a series of openings 88 for receiving a spherical ball connection 87 to which is fastened the upper end of a link 89 which extends to the tie base 59 of the folding bar assembly 48. More specifically, the lower end of the link 89 is connected by a spherical ball connection 91 to a mounting block 93 secured to the upper side of the tie base 59.

The lever ratio of the bell crank 83 may be varied by moving the connection 87 into any one of the seven holes 88 in upper am 94 of the bell crank 83. The bell crank 83 has a lower arm 96 to which is attached one end of a push rod 95 which is connected to a pivotally mounted cam follower wheel supporting arm 97. To assure that the push rod 95 does not bind as one end thereof moves in a generally horizontal plane about the pivot axis for the arm 97 while the other end moves in a vertical plane about the bellcrank pivotal axis at the pivot pin 84, spherical ball connections 99 are used to join the push rod 95 to cam follower arm 97 and to join the other end of the push rod 95 to the bell crank 83. The spherical ball connections 87, 91 and 99 are commercially available items and only the connection 99 between the push rod and the cam follower arm 97 shown in FIG. 7 will be described in detail. The connection 99 comprises a stud 100 having a threaded end inserted through an opening in the arm 97 and secured thereto by a nut 101 while on the opposite side of the arm 97 is a spherical surface 102 from which projects an upstanding threaded portion projecting through an aperture in one end of the push rod 95. A nut 103 is threaded to the top of the threaded portion to hold the push rod against the spherical surface 102. The end of the push rod 95 may rock slightly about the spherical surface 102 when driving the bell crank 83.

The cam follower are 97 carries a pair of cam fol lower wheels 107 and 109 mounted for turning movement about vertical axes and for rolling along the inner and outer sides of a vertically extending cam ring 105. To assure that the wheels 107 and 109 follow the contour of the cam ring 105 and to allow for any deviations in the thickness of the ring, the wheels 107 and 109 are biased into engagement with the cam ring 105 as will be described in greater detail. As best seen in FIGS. 2, 6 and 7, the cam follower arm 97 carrying the cam follower wheels 107 and 109 comprises a first or main section formed of two plates 111 and 112 for carrying directly the inner cam follower wheel 109 and a second or outer section in the form of a lever plate 113 pivotally mounted by a pin 1 14 to the main section plate 112 and carrying the outer cam follower wheel 107. The lever plate 1 13 is pivotally mounted for turning about a vertical axis by the pivot pin 114 which is mounted in a pair of vertically spaced bracket plates 115 welded at their inner ends to the lower plate 112 of the follower arm 97. The upper inclined plate 111 is joined to the lower plate 112 by vertical cross pieces 116.

At the respective outer ends the cam follower plate 1 12 and the outer end of lever plate 113, the inner cam wheel 107 and the cam follower wheel 109 are jour naled for rotation about vertically extending axes within box-like structures formed with a pair of depending side walls 118, as best seen in FIG. 6, and a lower bottom wall 119 disposed horizontally and fixed to the lower ends of the depending side walls 1 18. Vertically disposed wheel axles 120 are secured in the boxlike structures between the bottom wall 119 and the supporting overhead plates 112 and 113.

The inner and outer wheels 107 and 109 are biased into engagement with opposite vertical sides of the cam ring 105 by a biasing means in the form of a spring 121, as best seen in FIGS. 2 and 5, acting through a rod 122 extending horizontally across and above the cam ring 105 and connected to the respective main arm section and outer arm section. More specifically, the inner end of the rod 122 is pivotally mounted on an upstanding post 123 carried in box-like structure 124 formed on the top side of the main arm section. The rod projects through a similar box structure 125 carried on the upper side of plate 113 and through an aperture in a vertical post 126 carried in the box structure 125. The outer end of the rod 122 is threaded and carries a nut 127 which is threaded to compress the spring against the post 126. Thus, the spring 121 acts through the rod 122 to pull the inner follower wheel 109 against inner vertical surface of the cam ring 105 and to push the outer cam follower wheel 107 against the outer side of the cam ring 105.

The manner in which the cam follower means 33 is carried by the carrier 12 about the stationary cam ring 105 with the cam follou er wheels 107 and 109 following the contour of the cam ring 105 will now be described. Fastened to the carrier to rotate therewith is a huge can-like housing 128, as best seen in FIGS. 1, and 8, which is attached at its upper end to the frame 43 of the carrier 12. The can housing 128 is thin walled, cylindrical and coaxial with the longitudinal axis 28 through the carrier 12 and the flat mandrel 19. The can housing 128 serves to eliminate the effects of wind or air on the webs traveling from the carrier 12 across the web guide and folding bar means 17 to the mandrel 19. The cam housing extends from beneath the stationary upper floor 42 through an aperture in a second, lower stationary floor 129 carried by the box frame 27 to a lower end 130 beneath the floor 129. The portions of the slide bar assemblies 48 between the stationary floors 42 and 129 are supported by and are disposed closely adjacent to the inner side of the housing can 128.

Within the housing 128, as best seen in FIGS. 5, 6 and 7 is a supporting frame work 131 for the cam follower means 33 and the bell crank 83 which comprises a pair of vertically extending tubes 130 abutting the interior of the housing can 128 and fastened thereto at arcuately spaced positions. The tubes 130 are fastened at their upper ends to the carrier frame 37 and at their lower ends are fastened to a horizontally extending, annular wall 132 fastened to the can housing at the lower end thereof. The annular wall 132 projects radially toward but is spaced from the mandrel 19. The framework 131 further comprises a horizontally extending upper cross beam 133 fastened at opposite ends by brackets to opposite ends by the vertical tubes 130.

For the purpose of supporting the cam follower arm 97, a vertically extending post 137 is fastened at its upper end to cross beam 133 with its lower end fastened to annular wall 132 of the cam housing 128. Projecting outwardly through an opening cut in the can housing 128 and from a central portion of the post 137 is a cantilever mounting bracket 141 which serves to mount the cam follower arm 97 for pivotal movement about a vertical axis through a vertically extending pivot shaft 143 mounted at the outer free end of the bracket. As best seen in FIGS. 6 and 7, the cantilever bracket 141 is comprised of a pair of horizontally extending, upper and lower channels 144 and 145 spaced vertically from each other and secured at their inner ends to the main post 137 with their outer free ends spanned by a vertically extending channel 147. A pair of upper and lower triangularly-shaped gussets 149 extend between and are welded to the channels 144 and 145 and to the post to strengthen the bracket 14]. The pivot shaft 143 for the cam follower arm 97 is mounted in bearings carried by the channels 144 and 145 at their outer ends and adjacent the inside of the cam ring 105. Preferably, as best seen in FIGS. 6 and 7, the shaft 143 is extended upwardly and a strut 150 extends from the upper end of the shaft to a connection 151 with the plate 111 of the cam follower arm 97 to relieve some of the weight of the arm 97 at the bearings, thereby allowing free and better swinging of the arm 97 about the shaft 143. Thus, it will be seen that the cam follower arm 97 and its follower wheels 107 and 109 are carried by the carrier 12 and the can housing 128 for rotation with the carrier 12 about the mandrel l9 and the cam ring 105.

The bell crank 83 is also mounted in the supporting framework 13] on the inside of the can housing 128. More specifically, the pivot shaft 84 (FIGS. 6 and 7) for the bell crank 83 extends horizontally between a pair of vertically extending plates 153 and 154 which are disposed parallel to one another and project outwardly from the upper beam 133 to which they are attached at their upper ends. The plates 153 and 154 are each bolted to one of the upstanding C-shaped channel columns 85. As best seen in FIG. 6, each of the plates 153 and 154 carry inwardly facing bearings 155 for journaling the bell crank supporting shaft 84. As best seen in FIG. 5, the plates 153 and 154 are braced at their outer ends by angle braces 159 attached at first ends 160 to the plates 153 and 154 and at opposite ends 161 to the upper beam 133. Thus, the rigid framework 131 in the can housing 128 supports both the bell crank 83 and the cam follower arm 97 and carries both of them about the cam ring 105 as the carrier 12 revolves within the cam ring 105.

As best seen in FIG. 1 the cam ring 105 is secured to the lower horizontal stationary floor 129 of the frame 127 of the apparatus. More specifically, the illustrated cam ring has a flat horizontal sole plate 167 secured to the floor and an upstanding flange 169 secured to the sole plate. The illustrated cam flange 169 is l-inch thick and 6 inches in height which is secured to an I 1- inch wide sole plate 167 which is -inch thick. A rugged, strong cam ring 105 is needed to withstand the considerable forces involved with handling 84-102 inch webs of paper or the like and the very large folding bar assemblies, e.g., 20 feet in height and I0 feet in width. However, a portion of the weight of each folding bar assembly 48 is offset by using a spring means 170 in the form of large contractile springs 171 (FIG. 5) attached at the lower ends to the tie base 59 and at their upper ends to the carrier frame 37. The springs 17] act as counter weights and reduce the amount of lifting force needed by the bell cranks to raise the folding bar assemblies 48.

As stated previously, the cam ring 105 is constructed so that the folding bar and web guide means 17 is moved upwardly or downwardly to maintain a constant helix angle for the web applied to the mandrel 19, the helix angle being 42 to the horizontal in the example described herein. The web is laid on a downwardly traveling mandrel belt 21 or 23 and as the web thereon is carried downwardly by the belt, the folding bar assembly 48 of the web guiding and folding means 17 is shifting vertically so that the resultant web movement is substantially constant throughout the entire revolution of the carrier. The horizontal cam ring 105 causes the folding bar assembly to move vertically substantially in accordance with the curve shown in FIG. 10 and to travel either above or below a datum line 175. The datum line is where the horizontal component of web travel across the bar 18 is equal to the desired web velocity. In this example, the maximum travel of the bar 18 is about 24 inches with about l8 inches above the datum line 175 and 6 inches below the datum line.

In this example, the mandrel 19 is 93 inches in width from one side of the mandrel belt 21 to the other side of the mandrel belt 23 and the web 15 is laid at an angle of 42 to the horizontal. The web travel velocity is chosen, for example, 186 feet of web per revolution of the carrier 12. For a constant web velocity through each segment, e.g.. each 15 of turning of the carrier 12, approximately 7.75 feet of web should be unrolled and fed across the discharge bar 18 to the mandrel 19. With the helix angle of 42 and a 93-inch wide mandrel, he web 15 should travel downwardly on the mandrel belts a distance equal to product, cosine 42 X 93 inches or 84 inches for each half revolution of the carrier. Then, by drawing a layout of the actual position of the mandrel 19 relative to the bar 18 for each 15 of travel, the horizontal vector of web feed relative to the desired increment of 7.75 feet for each 15 of turning may be found. In this example, the actual horizontal vector accomplished at each 15 was found to be as follows: 3.05, 8.01, 10.89, 11.92, 12.07, 11.37, 10.25, 8.75, 71.3, 5.18, 3.13, and 1.25 feet. Then the desired 7.75 inches horizontal feed between each 15 location compared to the actual feeds above and the differences between the above and 7.75 inches feed were as follows: 3.l2; l.58; +0.26; +3.14; +4.17; +4.32, +3.62; +2.50; +1 .00; 0.62; 2.57; 4.62; and 6.50. Then a vertical displacement vector was found for each 15 location which when added to the actual horizontal feed vector gave a resultant and constant value of 7.75 feet. Thus, each of the net difference values above was divided by tangent 42 to give vertical vector displacements as follows: 3.47 down, 1.75 down, 0.288 up, 3.49 up, 4.63 up, 4.79 up, 4.02 up, 2.78 up, 1.11 up, 0.69 down, 2.86 down, 5.13 down and 7.20 down.

The values thus calculated for the vertical vectors are plotted to form a graph 180, FIG. 10, which shows that folding bar assembly 48 should be rising from point 181 at 22 to 182 at 124 for a total ascent over approximately 102 of travel. The folding bar assembly 48 will be descending for an arcuate extent of about 78 to point 183 which is located at 202 with the slope of the curve showing a faster descent than ascent. The bar assembly will then be ascending during the next 78 of arcuate travel about the mandrel 19 to a point 184 which is located at 304 from which it then begins to descend for the next 102 to return to the point 181.

The cam ring 105 is laid out as shown in FIG. 9 by drawing a base circle 187 having a diameter sufficiently wide to encompass the can housing 128 with the low points 182 and 184 for the cam ring 105 being located on the base circle 187. The cam ring 105 is then laid out with the displacements taken from graph and laid out along radial lines 188 taken at equal intervals, for example, 10, to provide a cam ring having the desired slope or rate of travel between the points 182 and 184 of maximum descent and points 181 and 183 of maximum ascent.

The folding bar assemblies 48 travel in a counterclockwise direction about the cam ring, as seen in FIGS. 1 and 9, and begin to rapidly descend when the cam wheels 107 and 109 roll along the cam ring past the points 182 and 184 adjacent the mandrel belts 21 and 23. The folding bars 18 on the tie bases 59 are located to trail the cam wheels 107 and 109 in counterclockwise direction so that the folding bars are rapidly descending when passing the mandrel belts 21 and 23. As a result, at the time of application of the webs to the mandrel belts 21 and 23, the folding bars 18 are descending at about the speed of the spirally wrapped tube 24 and the mandrel belts 21 and 23 thereby reducing the tendency of the webs to twist or rack on the mandrel belts as the webs turn the corners about them.

In copending application Ser. No. 96,756 and in the above-identified patent, the mandrel was described as being rotated in a direction opposite to the direction of carrier rotation and at the same speed as the carrier by an orbital drive system carried on the carrier and connected to the post from which the carrier was suspended. This orbital drive system also was used to drive the mandrel belts on the mandrel. However, in the present invention, the mandrel 19 is stationary and the mandrel belts 21 and 23 are driven by a long drive shaft (FIG. 8) which extends through the hollow interior of the carriers supporting post 29 and upwardly through the upper portion of the frame 27 to a variable speed drive mechanism 186. The speed of the mandrel belts 21 and 23 is controlled by varying the input speed to the shaft 185 from the variable speed drive mechanism 186 and this speed is closely controlled relative to the rotational speed of the carrier 12.

As best seen in FIG. 8, drive means 187 and 188 are provided for driving web unwind mechanisms 189 which have web unwind belts 190 in driving engagement with the respective parent rolls 14. These respective drives 187 and 188 are generally similar and each includes a variable speed input drive 192 and 193, respectively, by which the speed of a web unwind for its associated parent roll may be adjusted. The web unwind drive means 187 includes a vertically disposed shaft 195 mounted for rotation in the stationary frame 27 and having at its lower free end a pinion gear 196 mesh with a large gear 197 fixed to the upper end of a central sleeve 199 encircling the post 29. Fixed to the lower end of the sleeve 199 is an output gear 201 which drives a gear 202 fastened to the upper end of a vertical shaft 204 which in turn drives one of the belt unwind mechanisms 189. The shaft 204 is carried by and journaled for rotation in the carrier 12 which, in turn, rotates about the post 29 and will carry the gear 202 on the shaft 204 in a planetary movement about the gear 201. The latter, of course, is being rotated to provide the desired speed of unwind by the variable speed drive 192. In a like manner, the other drive means 188 includes a similar vertical shaft 195a driven by its variable speed drive 193. Fastened to the lower free end of the shaft 1950 is a pinion gear 196a driving a wide central gear 206. The wide gear 206 encircles the sleeve 199 and serves as input to gear 202a fastened to the upper end of a shaft 204a. The gear 2020 will partake of a planetary travel about the wide gear 206 as the carrier 12 rotates and carries the shaft 204a about the post 29. The lower end of the shaft 204a is suitably connected to the other web unwind mechanism 189 for the other parent roll 14 to cause its web 15 to unwind.

As disclosed in the aforementioned patent and copending application, the speed of the nip rolls 25, the rotational speed of the carrier 12, the speed of the web unwind drive mechanisms 187 and 188, and the speed of travel of the mandrel belts 21 and 23 are closely correlated and controlled to maintain the webs 15 and product 26 taut and unwrinkled. To these ends, each of the respective variable speed drive mechanisms 186, 192 and 193 may be adjusted to assure that the webs 15 are properly tensioned for travel along the web guide and folding bar means 17 and down along the mandrel 19.

A brief description of the operation of the illustrated apparatus 11 will be given as an aid to understanding the invention. The carrier 12 is driven to rotate about a vertical axis 28 through the supporting shaft 29 with the folding bar assemblies 48 being carried in a circular path about the mandrel 19. The webs 15 are continuously unwound from the parent rolls l4 and travel beneath dancer bars 34 to an upper horizontally extending folding bars 46 about which the webs change the direction of travel from that in horizontal direction to a vertical direction. The webs 15 extend straight down- 1 1 wardly from the folding bars 46 to engage inclined folding bars 47 along considerable lengths thereof from uppermost points which are above the plane of the carrier floor 40, as shown in FIG. 1, to lower points which are well within the can housing 128 beneath the carrier floor 40. The webs 15 are wrapped about the inclined folding bars 47 and travel through a narrow slot 190, as shown in FIG. 4, formed by the offsetting of the inclined folding bars 47 from the vertical plane common to the remaining bars 51, 67, 49 and 18 in each of the folding bar assemblies 48. The webs 15 are wrapped about the vertically extending folding bars 18 and travel downwardly to the mandrel belts 21 or 23 along the helix angle which in this instance is 42 to a horizontal plane. The folding bars are so arranged that each point on each web travels through a substantial equal distance as each web has its direction and inclination changed to be in an on-edge condition at the helix angle to the mandrel. Thus, the webs will remain taut and unwrinkled while on the folding bar assemblies 48.

As the carrier 12 rotates the folding bar assemblies 48 in a circular path, the cam means 32 and cam follower means 33 are shifting the folding bar assemblies 48 vertically in accordance with the curve 180 shown in FIG. 10. In this instance, the cam wheels 107 and 109 travel along the cam ring 105 and at points 182 or 184 adjacent one of the mandrel belts 21 or 23, the cam follower arms 97 pull the push arms 95 to pivot the bell cranks 83 about their pivot shafts 84 to force the links 89 downwardly, which in turn push the folding bar assemblies 48 downwardly as the webs 15 on the folding bar 18 approaches the mandrel belts. When the webs l touch the mandrel belts 21 and 23, the folding bar assemblies 48 should be traveling downwardly at substantially the speed of the travel of the spirally wrapped tube 24 on the mandrel 19. Thus, the opposite longitudinal edges of the webs should have about the same tightness; and, during the entire wrapping of the webs 15 from the first point to the last point on the belts, the webs 15 are at the angle of 42.

As the cam follower wheels 107 and 109 continue to roll along the cam 105 to the points 183, the folding bar assemblies 48 continue to descend but at the points 181 and 183, they begin to rise for the next 102 of travel on the cam ring 105. In this travel, the follower wheels 107 and 109 and the follower arms 97 push the push arms 95 inwardly, forcing the lower ends of the bell cranks 83 inwardly and pivoting the connections 87 to the links 89 upwardly. thereby pulling upwardly on the links 89 fixed to the tie bases 59 of the respective bar assemblies 48. These lifting forces are assisted by the stretched contractile springs 17] which exert upward lifting forces on the tie bases 59. In their vertical travels, the folding bar assemblies are guided for rectilinear movement by the ball bushes 73, 74 and 75.

Thus, the spirally wrapped tube 24 is formed on the mandrel 19 with the longitudinally extending edges of the webs disposed at an inclination of 42 to the longitudinal direction of the tube 24 which is flattened at the pair of nip rolls 25 to form a 4-ply bias laid ribbon product 26 having plies bias laid to one another and to the longitudinal direction of the ribbon product 26. As best seen in FIG. 8, the bias laid ribbon product 26 is. in this instance, sent through a three-high stack of press rolls 191 and about idler rolls 192 to the nip of a pair ofem- [Missing rolls 193 which assist in joining the plies togctht: lac plies may als in {Jil ed b .1 suitable tlllhU- an n ribbon product 'illtls i: .l lll'tn means 12 194 which slits the wide ribbon into a plurality of strips which are wound into a coil on a rewind 195.

From the foregoing, it will be seen that the fold bar assemblies 48 of the web guide and folding means 17 are shifted vertically in a controlled manner as they are carried by the carrier 12 in a circular path at a fixed radial distance from the center of the flat mandrel 19. While the mandrel 19 may have only the two belts 21 and 23, the mandrel 19 also may have several additional spacer bars (not shown) intermediate the two belts to provide some curvature and support for the tube 24, particularly on the lower end of the mandrel 19. Even so, the mandrel 19 is generally a flat mandrel as contrasted to the circular or elliptical shape mandrels shown in U.S. Pat. No. 3,580,784. The vertical shifting of folding bar assemblies is particularly useful where the webs 15 are creped tissue webs with longitudinally extending threads or filaments bonded thereto which eliminate some of the stretch and give of crepe tissue. The crepe tissue webs 15 become less accommodating to changes in directions and angular changes when reinforced in this manner. The apparatus is not limited to webs of creped tissue as webs of other material may be used.

While two webs 15 have been illustrated as being wound on the mandrel, it will be appreciated that a single web could have been wound to make a two-ply product as disclosed in U.S. Pat. No. 3,580,784. This patent also discloses that more than two webs may be applied to the mandrel and that the multi-ply product may have more than two plies, e.g., four or more plies. The present invention may be used with various widths of webs applied at various angles and speeds to mandrels of differing sizes. For such changes from the illustrated embodiment of the invention, the folding bar shifting means may be designed to shift the web vertically for a substantially uniform travel speed onto and along the mandrel. Usually, this may be accomplished most easily by re-designing the cam to shift the web folding and guiding means to maintain a substantially constant web speed for the new parameters.

From the above, it will be seen that with the present invention there is achieved an improved control of webs in a biasing laying apparatus and the bias laid webs may be flattened to form an aesthetically pleasing and unwrinkled bias laid ribbon product.

While a preferred embodiment has been shown and described, it will be understood that there is no intent to limit the invention by such disclosure but, rather, it is intended to cover all modifications and alternate constructions falling within the spirit and scope of the invention as defined in the appended claims.

We claim:

1. An apparatus for generally helically winding at least one web into a tube and for flattening the tube to form a multi-ply bias-laid ribbon, said apparatus comprising:

a carrier rotatable in a circular path about a vertical axis, means for supporting and carrying at least one parent web roll in a circular path about said axis and in a horizontal plane and from which a web travels forwardly, a vertically extending mandrel centered on said vertical axis and having horizontally spaced areas for contacting and for carrying said web vertically and at a substantially constant speed to discharge continually as a tube. folding bar means on said carrier movable in a circular path and at a fixed radial distance from said axis guiding said web and discharging the web to each of said mandrel areas at a predetermined angle, said folding bar means traveling from positions closely adjacent each of said horizontally spaced mandrel areas outwardly therefrom for a predetermined arcuate extent and then traveling inwardly toward the other of said spaced mandrel areas to positions closely adjacent to said other mandrel areas, means for shifting said folding bar means to ascend and descend relative to said mandrel and to said carrier during said circular path rotation of said carrier and said folding bar means to provide a substantially uniform travel of said web onto said mandrel and vertically along said mandrel and means for removing said tube from said mandrel and for flattening said tube into a multi-ply biaslaid ribbon.

2. An apparatus in accordance with claim 1 in which said means for shifting said folding bar means comprises a cam ring disposed in a horizontal plane and a cam follower means for converting horizontal displacements by said cam ring into vertical displacements of said folding bar means.

3. An apparatus in accordance with claim 2 in which said cam follower means comprises a cam follower arm pivotally mounted for turning a horizontal plane and further comprises a pair of rollers engaging opposite sides of said cam ring.

4. An apparatus in accordance with claim 3 in which said cam ring is contoured to displace said cam follower arm and to shift vertically said folding bar to provide asubstantially constant resultant movement of the web across said folding bar dui'ing equal portions of the carriers revolution.

5. An apparatus for forming a non-woven, bias laid, multi-ply product from at least one web comprising a mandrel of non-circular cross section disposed vertically and centered on a vertical axis and including at least two vertically moving belts, a rotatable carrier mounted for rotation in a circular path about said axis and for carrying a web supply roll in a circular path about said axis and in horizontal plane, web guide and discharge means carried by said carrier movable in a circular path about said axis and guiding said web and discharging the web while wrapping the same about said mandrel belts in a tubular arrangement, cam means for shifting said web guide and discharge means vertically during said cricular path rotation of the carrier to provide a more constant discharge angle and a more uniform velocity for the web travel with ascending and descending movement of said web guide and discharge means during rotation of the carrier, and means on said carrier for guiding said web guide and discharge means for rectilinear vertical movement while circling said mandrel.

6. An apparatus in accordance with claim 5 in which said mandrel is flat in cross section and in which said web is applied thereto at diametrically opposite positions, and in which said means for shifting said web guide and discharge means provides a maximum vertical displacement thereof when applying said web to said mandrel at one of said positions.

7. An apparatus for generally helically winding at least one web into a tube and for flattening the tube to form a multi-ply bias-laid ribbon, said apparatus comprising:

a carrier rotatable about a vertical axis and carrying at least one parent web roll from which a web travels forwardly, a vertically extending mandrel having horizontally spaced areas for contacting and for carrying said web vertically and at a substantially constant speed, folding bar means on said carrier for guiding said web and for discharging the web to the mandrel at a predetermined angle, means for shifting said folding bar means vertically relative to said mandrel during rotation of said carrier to provide a substantially more uniform travel of said web onto and vertically along said mandrel, said means for shifting said folding bar means comprising a cam ring disposed in a horizontal plane and a cam follower means for converting horizontal displacements by said cam ring into vertical displacements of said folding bar means, said folding bar means comprising a slide mounted on said carrier for rectilinear vertical movement and a folding bar carried by said slide for movement therewith vertically.

8. An apparatus in accordance with claim 7 in which said mandrel is suspended from said rotatable carrier and is driven in opposite direction to that of the carrier and at the same speed of rotation as the carrier, said folding bar traveling about said mandrel and said axis at a fixed radial distance.

9. An apparatus for forming a non-woven, bias laid, multi-ply product from at least one web comprising a mandrel formed of non-circular cross section disposed vertically and centered on a vertical axis, a rotatable carrier for rotation about said axis and for carrying a web supply roll, web guide and discharge means carrier by said carrier for guiding said web and for discharging the web while wrapping the same about said mandrel in a tubular arrangement, means for shifting said web guide and discharge means vertically during rotation of the carrier to provide a more constant discharge angle and a more unifonn velocity for the web travel during rotation of the carrier, said mandrel being flat in cross section, said web being applied thereto at a diametrically opposite positions, said means for shifting said Web guide and discharge means providing a maximum vertical displacement thereof when applying said web to said mandrel at one of said positions, said web guide and discharge means including a vertically shiftable slide having a folding bar thereon movable vertically while remaining at a fixed radial distance from said vertical axis, and said shifting means comprising a horizontally disposed cam ring and a cam follower means displaceable by said cam ring and connected to said slide to displace the latter vertically.

10. An apparatus in accordance with claim 9 in which said carrier comprises a cylindrical housing for rotation with said carrier, said slide being mounted internally of said housing and said cam ring being mounted externally of said housing, said cam follower means comprising a rolling cam follower and a cam follower arm for supporting the same, said cam follower arm being pivotally mounted for swinging about a vertical axis and carried by said cylindrical housing about said cam ring with said rolling cam follower being displaced by said cam ring and swinging said cam follower arm, a push rod extending from said cam follower arm, a bellcrank connected to said push arm and pivoted thereby about a horizontal axis, and a link means connecting said bellcrank to said slide to displace said slide vertically with pivoting of said bellcrank. 

1. AN APPARATUS FOR GENERALLY HELICALLY WINDING AT LEAST ONE WEB INTO A TUBE AND FOR FLATTENING THE TUBE TO FORM A MULTI-PLY BIAS-LAID RIBBON, SAID APPARATUS COMPRISING: A CARRIER ROTATABLE IN A CIRCULAR PATH ABOUT A VERTICAL AXIS, MEANS FOR SUPPORTING AND CARRYING AT LEAST ONE PARENT WEB ROLL IN A CIRCULAR PATH ABOUT SAID AXIS AND IN A HORIZONTAL PLANE AND FROM WHICH A WEB TRAVELS FORWARDLY, A VERTICALLY EXTENDING MANDREL CENTERED ON SAID VERTICAL AXIS AND HAVING HORIZONTALLY SPACED AREAS FOR CONTACTING AND FOR CARRYING SAID WEB VERTICALLY AND AT A SUBSTANTIALLY CONSTANT SPEED TO DISCHARGE CONTINUALLY AS A TUBE, FOLDING BAR MEANS ON SAID CARRIER MOVABLE IN A CIRCULAR PATH AND AT A FIXED RADIAL DISTANCE FROM SAID AXIS GUIDING SAID WEB AND DISCHARGING THE WEB TO EACH OF SAID MANDREL AREAS AT A PREDETERMINED ANGLE, SAID FOLDING BAR MEANS TRAVELING FROM POSITIONS CLOSELY ADJACENT EACH OF SAID HORIZONTALLY SPACED MANDREL AREAS OUTWARDLY THEREFROM FOR A PREDETERMINED ARCUATE EXTENT AND THEN TRAVELING INWARDLY TOWARD THE OTHER OF SAID SPACED MANDREL AREAS TO POSITIONS CLOSELY ADJACENT TO SAID OTHER MANDREL AREAS, MEANS FOR SHIFTING SAID FOLDING BAR MEANS TO ASCEND AND DESCEND RELATIVE TO SAID MANDREL AND TO SAID CARRIER DURING SAID CIRCULAR PATH ROTATION OF SAID CARRIER AND SAID FOLDING BAR MEANS TO PROVIDE A SUBSTANTIALLY UNIFORM TRAVEL OF SAID WEB ONTO SAID MANDREL AND VERTICALLY ALONG SAID MANDREL AND MEANS FOR REMOVING SAID TUBE FROM SAID MANDREL AND FOR FLATTENING SAID TUBE INTO A MULTI-PLY BIAS-LAID RIBBON.
 2. An apparatus in accordance with claim 1 in which said means for shifting said folding bar means comprises a cam ring disposed in a horizontal plane and a cam follower means for converting horizontal displacements by said cam ring into vertical displacements of said folding bar means.
 3. An apparatus in accordance with claim 2 in which said cam follower means comprises a cam follower arm pivotally mounted for turning a horizontal plane and further comprises a pair of rollers engaging opposite sides of said cam ring.
 4. An apparatus in accordance with claim 3 in which said cam ring is contoured to displace said cam follower arm and to shift vertically said folding bar to provide a substantially constant resultant movement of the web across said folding bar during equal portions of the carrier''s revolution.
 5. An apparatus for forming a non-woven, bias laid, multi-ply product from at least one web comprising a mandrel of non-circular cross section disposed vertically and centered on a vertical axis and including at least two vertically moving belts, a rotatable carrier mounted for rotation in a circular path about said axis and for carrying a web supply roll in a circular path about said axis and in horizontal plane, web guide and discharge means carried by said carrier movable in a circular path about said axis and guiding said web and discharging the web while wrapping the same about said mandrel belts in a tubular arrangement, cam means for shifting said web guide and discharge means vertically during said cricular path rotation of the carrier to provide a more constant discharge angle and a more uniform velocity for the web travel with ascending and descending movement of said web guide and discharge means during rotation of the carrier, and means on said carrier for guiding said web guide and discharge means for rectilinear vertical movement while circling said mandrel.
 6. An apparatus in accordance with claim 5 in which said mandrel is flat in cross section and in which said web is applied thereto at diametrically opposite positions, and in which said means for shifting said web guide and discharge means provides a maximum vertical displacement thereof when applying said web to said mandrel at one of said positions.
 7. AN APPARATUS FOR GENERALLY HELICALLY WINDING AT LEAST
 8. An apparatus in accordance with claim 7 in which said mandrel is suspended from said rotatable carrier and is driven in opposite direction to that of the carrier and at the same speed of rotation as the carrier, said folding bar traveling about said mandrel and said axis at a fixed radial distance.
 9. An apparatus for forming a non-woven, bias laid, multi-ply product from at least one web comprising a mandrel formed of non-circular cross section disposed vertically and centered on a vertical axis, a rotatable carrier for rotation about said axis and for carrying a web supply roll, web guide and discharge means carrier by said carrier for guiding said web and for discharging the web while wrapping the same about said mandrel in a tubular arrangement, means for shifting said web guide and discharge means vertically during rotation of the carrier to provide a more constant discharge angle and a more uniform velocity for the web travel during rotation of the carrier, said mandrel being flat in cross section, said web being applied thereto at a diametrically opposite positions, said means for shifting said web guide and discharge means providing a maximum vertical displacement thereof when applying said web to said mandrel at one of said positions, said web guide and discharge means including a vertically shiftable slide having a folding bar thereon movable vertically while remaining at a fixed radial distance from said vertical axis, and said shifting means comprising a horizontally disposed cam ring and a cam follower means displaceable by said cam ring and connected to said slide to displace the latter vertically.
 10. An apparatus in accordance with claim 9 in which said carrier comprises a cylindrical housing for rotation with said carrier, said slide being mounted internally of said housing and said cam ring being mounted externally of said housing, said cam follower means comprising a rolling cam follower and a cam follower arm for supporting the same, said cam follower arm being pivotally mounted for swinging about a vertical axis and carried by said cylindrical housing about said cam ring with said rolling cam follower being displaced by said cam ring and swinging said cam follower arm, a push rod extending from said cam follower arm, a bellcrank connected to said push arm and pivoted thereby about a horizontal axis, and a link means connecting said bellcrank to said slide to displace said slide vertically with pivoting of said bellcrank. 